A U.S. military official confirmed to NBC News that 'fewer than 100' Department of Defense personnel will augment security assets at U.S. diplomatic facilities in Baghdad.
The news comes as violence erupted throughout Iraq's capital — at least 15 people were killed and more than two-dozen were injured in explosions on Sunday, Iraqi police and hospital officials told the Associated Press.
In central Baghdad, 10 were killed by a car bomb and two died during a night-time explosion. In the Sadr City district, three were killed during explosions at a falafel shop, the AP reported.
The U.S. Embassy in Baghdad remained open in the aftermath of the explosions, though security was strengthened and some staff members were transferred out of the city, a State Department spokeswoman said in a statement.
"The people of Iraq have repeatedly rejected violent extremism and expressed their desire to build a better society for themselves for their children," the statement said.
Iraq has spiraled into sectarian violence in recent days — last week, insurgents captured Iraq's second-largest city, Mosul.
The USS George H.W. Bush and two other U.S. Navy ships arrived in the Persian Gulf on Sunday, and Iraqi soldiers and militia fighters fought to fend off Sunni Islamic militants.
On Sunday afternoon, the streets of Baghdad were empty, and an overnight curfew was imposed.
Also on Sunday, a series of pictures posted to a Twitter account controlled by militants purported to show gunman shooting unarmed men. The authenticity of those pictures has not been independently verified by NBC News.
—Tim Stelloh and Courtney Kube